This invention relates to apparatus which produces labels by adhesively bonding a transparent overlay tape material in covering relation to the printed surface of an opaque base tape material and, more particularly, to such an apparatus which is a unitary, stand-alone unit for positioning adjacent a computer printer having a tractor-type paper feed mechanism. The apparatus is operable to concurrently deliver a continuous web of blank base tape material to the printer, receive the web of printed base tape material therefrom, and adhesively apply a continuous web of transparent overlay tape material thereto thereby producing a continuous web of smudge-proof, dirt-resistant labels which are cut or otherwise separated from the web into individual labels for application to a substrate such as the binding of a library book, for example.
The type of base and overlay tape materials preferably used to make the labels with the present invention are disclosed in prior U.S. Pat. No. 4,564,411. The '411 patent discloses three different embodiments of label producing apparatus which operate by detachably mounting to a typewriter or printer having rolling, movable and fixed platens. In each of the embodiments, individual spools of the base tape material and overlay tape material are rotatably mounted upon respective spindles and are unwound therefrom and ultimately directed between an upper, pressure-loaded roller and a lower drive roller which are rotatably mounted with tangent surfaces in rolling engagement with one another. In two of the three embodiments which detachably mount to typewriters having rolling, and moving and rolling platens, respectively, the typewriter platen serves as the drive roller. In the embodiment which detachably mounts to a printer having a fixed platen and sheet-feeding tractor mechanism, the drive roller shaft of the label producing apparatus coaxially connects to the drive shaft of the sheet-feeding tractor mechanism of the printer. The base tape material spool is mounted via a second assembly to an internal portion of the printer housing with the base tape material being directed upwardly therefrom, between the fixed platen and printer head of the printer, and between the feed rollers which are located thereabove on the printer housing.
While the invention of the '411 patent improved upon such label producing apparatus in existence at that time in the manners stated therein, there remain obvious drawbacks in having to mount the label producing apparatus, albeit non-permanently, to the typewriter or printer. For example, besides the set-up time involved in mounting the label producing apparatus to the typewriter/printer, a certain level of mechanical ability is required which may pose difficulties for a large segment of the user population. Also, certain portions of the label producing apparatus are directly attached to the typewriter/printer requiring, in at least some instances, that holes be drilled into portions of the typewriter/printer. Furthermore, since the label producing apparatus of the '411 patent is operably connected to the typewriter/printer, it is necessary that sizes, diameters and tolerances between the connected working components be substantially compatible.